How to observe multiple downloads by id ?

[tosam144]

Thank you for this great library!

I don't know how to observe many downloads by ID. This is what I tried to do within my AndroidViewModel:

viewModelScope.launch {
        val filesToDownload = loadDownloads()
        filesToDownload.forEach { doc ->
                         val id = ketch.download(...)
                         viewModelScope.launch {
                                    ketch.observeDownloadById(id)
                                            .flowOn(Dispatchers.IO)
                                            .collect { downloadModel -> 
                                                   // Process the downloaded file if status == SUCCESS
                                                   if (downloadModel.status == Status.SUCCESS) {
                                                          Timber.d(downloadModel.url)
                                                   }
                                           }
                         }
               }    
        }

Function loadDownloads() is a suspend function which must run in its own IO coroutine. However, this approach does not work because I get multiple calls to the observe (probably due to the nested coroutines). If I omit the inner coroutine, it won't work either. The issue is, I must process each download right after the file is successfully downloaded. How do I solve this issue? Thank you so much.

[khushpanchal]

you can write separate observe function

fun observeDownloads() {
list.forEach { // list of ids provided by ketch
viewModelScope.launch {
ketch.observeDownloadById(it).distinctUnitChanged().flowOn(Dispatchers.IO).collectLatest {
// here you can check when download is success.
}
}
}
}

another approach to observeAllDownloads at one place
fun observeAllDownloads() {
viewModelScope.launch {
ketch.observeAllDownloads().distinctUnitChanged().flowOn(Dispatchers.IO).collectLatest {
// here you will get complete downloads list, and you can do the pre processing
}
}

Also I will be publishing new version of ketch by this weekend, there I will be adding another method to observeDownloads by multiple Ids.